Metallic link chain.



E. A. BOHLMAN.

METALLIC LINK CHAIN.

APPLICATION-FILED DBO. 4, 1911.

1, 1 03,026. Patented July 14, 1914.

2 SHEETSBHEET 1.

6 a. xi i/6, v

E. A. BOHLMAN.

METALLIC LINK CHAIN.

APPLIUATION FILED DB0.4,19111 Patented July 1%, 19M.

2 SHEETS-SHEBT 2.

i Fig. 9 in the mannerwhich 'will hereafter.

UNITED sTArEs PATENT OFFICE.

ERNEST A. IBOHLIAN, OF CEDAR RAPIDS, IOWA, ASSIGNOR TO PEERLESS V BELT COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

METALLIG LINK CHAIN.

Specification of Letters Patent.

Application filed December 4, 1911.

Patented July 14, 1914.

Serial No. eas,s4o.

features an improvement upon Patent Number 875,426 for drive belt, issued December '21, 1907 to A. H. Gits.

The-object of the invention is to do away with some bad features which exist in the devices of said prior patents. I

More particularly he object of the mvention is to provide a pivot device for the links thereof in which the bars forming the pivot are so mounted on the link members that they cannot readily tear loose from the link members and then wear into the link members, with consequent irregular lengthing of the chain.

The object of the invention is further to rovide a novel form and quality of flexile material on the outside of the chain which will very readily grip the pulleys over which the'chain passes.

The invention consists in a device capable of carrying out the foregoing ob ects wh ch can be very easily and cheap y made, wh ch is easily assembled and taken apart, which is satisfactory in operation, and not readily liable to get outof order.

Figure 1 is a side view, and Fig.2 a plan, of a chain of this invention, the two left hand links of each figure being shown in full, the remaining two links being partially dismantled. Figs. 3, 4,' 5 and 6 are details of diflerent parts of the chain. Flg. 7 is a detail sectional view of one link taken on the line? of Fig; 2. Fig. 8 is acorrespondin detail view taken on theline 8 of Fig. 2. ig. '9 is a perspective detail view of the compound rivet for finally securing the parts of a complete link of the chain together. Figs. '10, 11 and 12, are details of the parts used in connection with the device of clearly appear. Fig. ,13 .slmws the middle plate of the secondary link 16 in a form of construction which may be used in this de: vice. Fig. 14 is a perspective view of a modified form of the pin 80, for use in the construction of Fig. 13. Fig. 15 is a sectional detail view on the line 15-45, when the device of Fi s. 13 and 14 is used.

As in both 0 said prior patents, the 'device, broadly speaking, consists in a plurality of primary links 15 connected together by secondary links 16 pivoted to the primary links, the primary links of this chain being inclosed upon the wearing side by a piece of friction material 17 secured thereto by rivets 18 passing vertically through the centers of the primary links. The chain of this invention, however, differs from those of the prior patents above referred to, in that the friction material is a specially treated canvas and does not run continuously the entire length of the chain; in the specially constructed rivets 18, and in the form and construction of the pivotal joints between the links.

.The primary links 15 are constructed of two bars 20 and 21 having respectively vertical faces 22 and 23 adapted to lie close to the vertical walls of the secondary links 16 and having inclined outer faces 24 and 25 corresponding in angularity to the wallsof the groove of the pulley in which the chain is to run. Depending from the lower p01.

tionsof the bars 20 and 21 are lugs 28, and extending fromtheopposite upper faces of these bars are other projecting lugs-30 havmg opposite substantially parallel vertical faces 2.

Above each pair of connecting members 20 and 21 is placed a connecting plate of metal 35 having therein a lurahty' of perforations oropenings 34 a apted to be entered by the In s 30 and adapted to be engaged by the aces 32 thereof to thereby prevent spreading of the bars 20 and 21 away from each other. On the late 35 is placed a block 36 of leather, fi her, press oa'rd, hard rubber or any other friction material, and over this block 36 is laced a pro? jecting metal plate 37. The plate 35, heretofore referred to, is provided with a Inrality of projecting prongs .38 which are driven into the under side of the block 36, and the plate 37 is provided with corresponding projections 39, which re driven into' the upper surface of the b' ock 36 so no that when these two plates are supplied to other and thus make an elongated central opening through the metal covered block 36. This slot 40 heretofore referred to, is located in approximately the center of this metal covered block 86 and in such aposition that when the block is placed upon the bars 20 and 21 of the primary link with the lugs 30 thereof entering the recess 34 in the plate 3."), the slot 40 extends crosswise of the length of the primary. link at its center and. is directly over the opening which always exists in the center of the primary link between the ends of the secondary links. Around the lower or bearing portion of each primary link 15 of the .chain is placed a piece of canvas 42 extending, as clearly appears in Fig. 8, up the sides of the primary link-to approximately the lower edge of the plate Belowthis canvas member 42 is a small metal plate or Washer 44 having through its center aslot 46 in the same vertical plane as the slot 40 heretofore referred to.

Through the canvas 42 and the slots 40 and 46 are placed the compound rivets 18 comprising, as here shown, two parallel bars or strips of metal .of approximately the same length having their ends 48 bent over at the top and bottom, as shown, to hold all of the parts of the primary link together,

In the rior' devices, above referred to, ordinary rivets have been used in connection with chains of this class, but they are objectionable because the heads of the rivets being made by the pounding action of a hammer are liable to bend and interfere with the pivot of the primary link and it is impossible-to spread the heads evenly and thus secure a uniform tension on all parts of the link which .isr'to be secured together by this device, whereas, with the rivets 18, here used, the secui'ing is obtained by bending the ends 48 from the full line position (on the left hand half of the rivet as shown in Fig. 9) to the dotted line osition in that part of said figure, which ending can be done accurately, and when done will hold the parts with a uniform tension and considerable more anchoring surface. Aside from this, the rivet 18 is advantageous in that being-fiat it occupies less space between the ends of the secondarylinks 16 and thereby'with a given strength of chain makes it possible to use shorter links, which is frequently advantageous.

In order to make the chain more satisfactorily gri the I ulley over which it runs, than has een t e case with prior devices above mentioned, the canvas friction strips 42 are treated, ordinarily before application to the chain, with a composition consisting of approximately seventy-six'per cent. pitch, twenty-two and one-half per cent. a'sphal-- tum and one and one-half per cent. shellac.

In the plate 44 and immediately adjacent to the ends of the slot 46 are recesses 50 registering with the lugs 28 on the lower edges of the bars 20 and 21. These lugs 28 engage the canvas strip 42 immediately above these recesses50, and when the parts of the rivet 18' are bent tothe position of Fig. 7, pressv links. and may be made of one piece of metal, butare preferably made of .a plurality of thin sheets 52, as clearly appears in Fig. 2. i

In the prior art, as illustrated in Patent Number 979,151 heretofore referred to, the primary and secondary links are pivoted together, by means of members which have suitably curved surfaces in rolling contact with eachother, the contacting members being supposedly secured to their respectiveprimary or secondary links in a rigid manner', but the rolling action above. referred to produces so much strain upon the securing devices there shown for fastening the pivot members to their respective rimary and secondary links, that the pi ot members break loose from said link parts, and, first do not work properly, thereby creating friction, and, finally, grind into the link parts proper, thereby materially injuring the efficiency of the device. In the construction of this'in-venticn, this difliculty is entirely obviated. This result is obtained by cutting in each end of the bars 20 and 21 an opening 54 of the shape illustrated in detail in the left hand end of Fig. 3, the opening :being bounded by the curved face 56, the straight face 58 and the faces of two opposite inwardly projecting ridges 60, as shown. In

the triangular space formed between thefaces 58 and the adjacent faces of the ribs 60 is inserted the correspondingly shaped end 62 of a bearing pin 64 having the hardened rib 66 running lengthwise, as shown. The center portion of this pin 64 has a curved surface 68 on theopposite side from therib 66 and between the end portions 62 heretofore described. The length of this curved surface 68 is substantially equal to or slightly greater than the thickness of the secondary link 16, while the length of the endportion 62 of the members 64 is sub stantially equal to or less than the thickness of the bars and 21 of the primary link. When the pins 64 are in position with referenoe to the bars of the primary link, the inner walls of said links bear against the shoulders 69 formed at the ends of the surface 68 on member 64 as shown. Similarly each secondary link 16 has cut in its opposite ends holes 70 bounded respectively by the curved surfaces 72 and 74 and the walls of the' inwardly projecting ribs 76. Driven into the space formed by the surface 74 and the adjacent faces of the ribs 76, is a pin 7 8 suitably shaped,- as shown in Fig. 6, having a bearing face 80 provided with a recess 82 designed to register with the ridge 66 on pins 64. When the parts are in assembled position, both of the contacting surfaces being thoroughly hardened, all of the pivotal action between the adjacent primary and secondary links takes place along this ridge 66. As pin 78 is rigidly secured in its secondary link and as pin 64 is rigidly secured in its primary link in the manner heretofore described, it is impossible for these parts to get loose and transfer thepivotal action of the bearing to any other point. I

In the assembling of the entire device, the secondary links 16 are provided with their pins'78 ordinarily secured in place so tightTy thatthey are not easily removable. The operator now takes one of the, bars of a primary link, places its pivotal pin 64 in place therein and inserts said pin 64 through the larger portion of the opening 70 in the adjacent secondary link with the ridge 66 in contact with the recess 82 .and then places the other bar of the primary link in position over the second end. of the pin 64. When both ends of the given primary links have been thus connected to a secondary link, he places a canvas friction member 42 about the lower portion of the primary link, places the plates 44 in contact therewith and inserts the compound members of the pin 1.8 therethrough between the parts of the primary link and the ends of the secondary and thereupon places the metal plated block in position, as shown, and bends the respective ends 48 of the securing pin 18 to the position of Fig. 7 This completes one link; the remaining links of the chains are made in the same way. If occasion arises for taking the chain apart, it is only necessary to bend the ends 48 of each half of the pin 18 until they are perpendicular with the block 36 and thus remove the pin and take the particular link in hand apart.

In the foregoing description, thepin 80 has been merely driven into the link 52 and held there by frictional contact. In practice, it is frequently \preferable to secure this pin by mechanical means. In order to do this, a modified form of pin 80 is provided having in its center notches 90 of substantially the width of the central member 52 of the secondary links 16. The member 52 of this link has cut in it holes 92, corresponding to the holes 70, heretofore described, but modified by the use of the rectangular shoulders 94 designed to receive the portion of the member 80 which contains the notches 90, With the result that the metal of member 8O adjacent to these shoulders 94 rigidly holds the member 80 against endwise movement across the member 52" with the result that when the parts are assembled into the complete secondary link 16, the two outside members 52 being placed on each side of. member 52 and. on member 80 as heretofore described, the member 80 is mechanically rigidly held in the secondary link.

The claims are:

1. A link chain including a link member composed of three parallel plates, provided with a hole therethrough and a pivot pin inserted through said hole in the link, said pin being of-less cross sectional area than.

said hole in the link and secured to said link member byiengagement with non-circular portions of the'edge of said hole, the configuration of the non-circular portion of the hole in the middle member of the link being different from the configuration of the openings in the outside members of the 'link and the middle portion of the pin 'be ing of corresponding different cross section for the purposes set forth.

2. A link chain including a link member made up of three plates provided with an opening therethrough, and a pivot pin inserted through saidopenin in said link, the opening through the mid le plate of'the link being of a different diameter from the openings in the outer plates, and said pin having a correspondingly difierent cross section at its central portion.

In witness whereof l have hereunto subscribed my name in the presence of two witnesses.

ERNEST A. BOHLMAN. Witnesses:

J. E. CAGNEY, Jr., ALLEN H. METCALF. 

